The QLine class provides a two-dimensional vector using integer precision. More...

#include <qline.h>

Public Member Functions
constexpr	QLine ()

constexpr	QLine (const QPoint &pt1, const QPoint &pt2)

constexpr	QLine (int x1, int y1, int x2, int y2)

constexpr bool	isNull () const

constexpr QPoint	p1 () const

constexpr QPoint	p2 () const

constexpr int	x1 () const

constexpr int	y1 () const

constexpr int	x2 () const

constexpr int	y2 () const

constexpr int	dx () const

constexpr int	dy () const

void	translate (const QPoint &p)

void	translate (int dx, int dy)

constexpr QLine	translated (const QPoint &p) const

constexpr QLine	translated (int dx, int dy) const

constexpr QPoint	center () const

void	setP1 (const QPoint &p1)

void	setP2 (const QPoint &p2)

void	setPoints (const QPoint &p1, const QPoint &p2)

void	setLine (int x1, int y1, int x2, int y2)

constexpr bool	operator== (const QLine &d) const noexcept

constexpr bool	operator!= (const QLine &d) const noexcept

Related Functions
(Note that these are not member functions.)
QDataStream &	operator<< (QDataStream &stream, const QLine &line)

QDataStream &	operator>> (QDataStream &stream, QLine &line)

Detailed Description

The QLine class provides a two-dimensional vector using integer precision.

\inmodule QtCore

A QLine describes a finite length line (or a line segment) on a two-dimensional surface. The start and end points of the line are specified using integer point accuracy for coordinates. Use the QLineF constructor to retrieve a floating point copy.

\table \row

\inlineimage qline-point.png
\inlineimage qline-coordinates.png \endtable

The positions of the line's start and end points can be retrieved using the p1(), x1(), y1(), p2(), x2(), and y2() functions. The dx() and dy() functions return the horizontal and vertical components of the line. Use isNull() to determine whether the QLine represents a valid line or a null line.

Finally, the line can be translated a given offset using the translate() function.

See also: QLineF, QPolygon, QRect

Definition at line 52 of file qline.h.

Constructor & Destructor Documentation

◆ QLine() [1/3]

constexpr QLine::QLine ( )

inlineconstexpr

Constructs a null line.

Definition at line 98 of file qline.h.

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◆ QLine() [2/3]

constexpr QLine::QLine	(	const QPoint &	p1,
		const QPoint &	p2
	)

inlineconstexpr

Constructs a line object that represents the line between p1 and p2.

Definition at line 100 of file qline.h.

◆ QLine() [3/3]

constexpr QLine::QLine	(	int	x1,
		int	y1,
		int	x2,
		int	y2
	)

inlineconstexpr

Constructs a line object that represents the line between (x1, y1) and (x2, y2).

Definition at line 102 of file qline.h.

Member Function Documentation

◆ center()

constexpr QPoint QLine::center ( ) const

inlineconstexpr

Since: 5.8

Returns the center point of this line. This is equivalent to (p1() + p2()) / 2, except it will never overflow.

Definition at line 170 of file qline.h.

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◆ dx()

constexpr int QLine::dx ( ) const

inlineconstexpr

Returns the horizontal component of the line's vector.

See also: dy()

Definition at line 139 of file qline.h.

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◆ dy()

constexpr int QLine::dy ( ) const

inlineconstexpr

Returns the vertical component of the line's vector.

See also: dx()

Definition at line 144 of file qline.h.

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◆ isNull()

constexpr bool QLine::isNull ( ) const

inlineconstexpr

Returns true if the line does not have distinct start and end points; otherwise returns false.

Definition at line 104 of file qline.h.

◆ operator!=()

bool QLine::operator!= ( const QLine & line ) const

inlineconstexprnoexcept

Returns true if the given line is not the same as this line.

A line is different from another line if any of their start or end points differ, or the internal order of the points is different.

Definition at line 87 of file qline.h.

◆ operator==()

constexpr bool QLine::operator== ( const QLine & line ) const

inlineconstexprnoexcept

Returns true if the given line is the same as this line.

A line is identical to another line if the start and end points are identical, and the internal order of the points is the same.

Definition at line 197 of file qline.h.

◆ p1()

constexpr QPoint QLine::p1 ( ) const

inlineconstexpr

Returns the line's start point.

See also: x1(), y1(), p2()

Definition at line 129 of file qline.h.

◆ p2()

constexpr QPoint QLine::p2 ( ) const

inlineconstexpr

Returns the line's end point.

See also: x2(), y2(), p1()

Definition at line 134 of file qline.h.

◆ setLine()

void QLine::setLine	(	int	x1,
		int	y1,
		int	x2,
		int	y2
	)

inline

Since: 4.4

Sets this line to the start in x1, y1 and end in x2, y2.

See also: setP1(), setP2(), p1(), p2()

Definition at line 191 of file qline.h.

◆ setP1()

void QLine::setP1 ( const QPoint & p1 )

inline

Since: 4.4

Sets the starting point of this line to p1.

See also: setP2(), p1()

Definition at line 175 of file qline.h.

◆ setP2()

void QLine::setP2 ( const QPoint & p2 )

inline

Since: 4.4

Sets the end point of this line to p2.

See also: setP1(), p2()

Definition at line 180 of file qline.h.

◆ setPoints()

void QLine::setPoints	(	const QPoint &	p1,
		const QPoint &	p2
	)

inline

Since: 4.4

Sets the start point of this line to p1 and the end point of this line to p2.

See also: setP1(), setP2(), p1(), p2()

Definition at line 185 of file qline.h.

◆ translate() [1/2]

void QLine::translate ( const QPoint & offset )

inline

Translates this line by the given offset.

Definition at line 149 of file qline.h.

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◆ translate() [2/2]

void QLine::translate	(	int	dx,
		int	dy
	)

inline

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Translates this line the distance specified by dx and dy.

Definition at line 155 of file qline.h.

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◆ translated() [1/2]

constexpr QLine QLine::translated ( const QPoint & offset ) const

inlineconstexpr

Since: 4.4

Returns this line translated by the given offset.

Definition at line 160 of file qline.h.

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◆ translated() [2/2]

constexpr QLine QLine::translated	(	int	dx,
		int	dy
	)		const

inlineconstexpr

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Since: 4.4

Returns this line translated the distance specified by dx and dy.

Definition at line 165 of file qline.h.

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◆ x1()

constexpr int QLine::x1 ( ) const

inlineconstexpr

Returns the x-coordinate of the line's start point.

See also: p1()

Definition at line 109 of file qline.h.

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◆ x2()

constexpr int QLine::x2 ( ) const

inlineconstexpr

Returns the x-coordinate of the line's end point.

See also: p2()

Definition at line 119 of file qline.h.

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◆ y1()

constexpr int QLine::y1 ( ) const

inlineconstexpr

Returns the y-coordinate of the line's start point.

See also: p1()

Definition at line 114 of file qline.h.

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◆ y2()

constexpr int QLine::y2 ( ) const

inlineconstexpr

Returns the y-coordinate of the line's end point.

See also: p2()

Definition at line 124 of file qline.h.

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Friends And Related Function Documentation

◆ operator<<()

QDataStream & operator<<	(	QDataStream &	stream,
		const QLine &	line
	)

See also: {Serializing Qt Data Types}

Definition at line 287 of file qline.cpp.

◆ operator>>()

QDataStream & operator>>	(	QDataStream &	stream,
		QLine &	line
	)

See also: {Serializing Qt Data Types}

Definition at line 302 of file qline.cpp.

The documentation for this class was generated from the following files:

src/corelib/tools/qline.h
src/corelib/tools/qline.cpp

Public Member Functions

Related Functions

Detailed Description

Constructor & Destructor Documentation

◆ QLine() [1/3]

◆ QLine() [2/3]

◆ QLine() [3/3]

Member Function Documentation

◆ center()

◆ dx()

◆ dy()

◆ isNull()

◆ operator!=()

◆ operator==()

◆ p1()

◆ p2()

◆ setLine()

◆ setP1()

◆ setP2()

◆ setPoints()

◆ translate() [1/2]

◆ translate() [2/2]

◆ translated() [1/2]

◆ translated() [2/2]

◆ x1()

◆ x2()

◆ y1()

◆ y2()

Friends And Related Function Documentation

◆ operator<<()

◆ operator>>()